I. Field of the Invention
The present invention relates to a method for treating sewage and, more particularly, to a method for separating the combustible components of the sewage from the sewage scum.
II. Description of the Prior Art
As used herein, the term "sewage" refers not only to raw sewage but also to byproducts obtained during treatment of the sewage. Similarly, the term "scum" as used herein means the portion of the sewage which floats on top of the raw sewage and is conventionally skimmed from the top of the sewage.
Sewage scum is primarily composed of fats, oils, greases and the like, hereinafter sometimes collectively referred to as oils, intermixed with both water and assorted solid debris. Due to the water and assorted solid debris in the sewage scum, the sewage scum has a low combustibility and previously has been disposed of by grinding, landfill disposal, incineration and other methods. Such disposal of the scum, however, is not only expensive but is also a waste of a valuable energy source.